Belt fusers are popular for laser printers because of their nearly “instant on” characteristic, i.e., they are heated and prepared to fix toner onto media within a few seconds. The present operation of a conventional belt fuser is to be have the fuser turned off unless toner is being fixed. This mode of operation minimizes the energy used by the printer when it is not printing.
A belt fuser has a finite warm up time that is constrained by the physics (such as thermal capacitance and thermal impedance) of the fuser, the amount of power supplied to the fuser, the desired (target) temperature of the fuser, and the initial conditions of the fuser. Because of improvements in the time at which modern laser printers can generate an image, this finite warm up time has become the limiting factor in time to first print (TTFP). Since there is an interest in improving the time to first print in order to satisfy the user's expectations, a need exists for an improved method. However, any improvement in the time to first print still must meet the important power consumption requirements (such as the USA Environmental Protection Agency ENERGY STAR and German Blue Angel), as well as European flicker and harmonic requirements (IEC 61000-3-2 and 61000-3-3, respectively).
It would be an improvement to minimize the warm-up time of belt fusers in EP printers, while still meeting other important power operating parameters.